Armature for electric machines



(No Model.)

B. A. SPERRY. ARMATURE FOR ELECTRIC MACHINES.

Patenteduly' 19, 1892.

"WWlllllllllllllllllllllllll Illllll llul I UNITED STATES PATENT OFFICE.

ELMER A. SPERRY, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE THOMSON- IIOUSTONELECTRIC COMPANY, OF BOSTON, MASSACHUSETTS.

ARMATURE FOR ELECTRIC MACHINES.

SPIECIII1IC.A.[IO1\T forming part of Letters Patent N 0. 47 9,030, datedJuly 19, 1892. Application filed December 17,1891. SerialNo. 415,397.(No model.)

To all whom it may concern/,-

Be it known that I, ELMER A. SPERRY, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a new, useful, and Improved Armature for Electric Machines, ofwhich the following is a specification, reference being had to theaccompanying drawings, in which similar letters of reference indicatelike parts in all the figures.

In the drawings, Figure 1 is a longitudinal sectional view of a portionof an armature embodying my improvement. Fig. 2 is a cross section ofthe same through one of the hubs. Fig. 3 is a view showing the manner inwhich the supports overlap each other. Fig. 4 is a detail View showingan alternate form of securing the retaining-cap to the end of thearmature, all of which will be more fully explained hereinafter; andFig. 5 is another detail View of the core-supports.

My invention relates more particularly to ring-armatures; but somefeatures of it may be applied to drum-armatures as well, and, while itis designed that all features should be used together, some may be usedwithout the others.

My invention further relates to the method of supporting the core inring-armatures and to placing the binding upon the exterior surface,which last feature may also be applied to drum-armatures.

In the figures, A is the armature-shaft, and B is the armature-core,made up in the usual way of thin disks or rings of soft iron andinsulated from each other. The core is grooved longitudinally upon itsperiphery, as shown at d in Fig. 2, for the reception of thearmature-coils. Upon the ends of the armaturecore are the somewhatthicker rings E and E, through which and the core of the armature passthe insulated tie-bolts I. Upon the shaft A are two hubs C and C, keyedthereto by means of the keys J and J. These hubs are preferably formedwith the radially-projecting arms 0 and c, Fig. 1, and shown in sectionat c c c, Fig. 2.

H, H, H, and H are screw-bolts passing axially from one hub to theother, and by means of the nuts h on each of these bolts the hubs may bedrawn toward each other. The

arms 0 and c are grooved upon their outer edges, as shown in Fig. 2,where the grooves run parallel with the axis of the shaft, and in themare placed the radially-projecting thin supports S and S. Fig. 1, andshown in section at S, S, and S in Fig. 2. These supports are insulatedfrom the arms 0 c of the hubs, as shown in Fig. 2, and are securedtherein by the bolts or rivets n n, &c., which are of course alsoinsulated from the supports S and S.

The supports S and S are provided with the projections s and 3 upontheir outer ends and overlap one another at their inner ends between thehubs, as shown at no, Figs. 1 and 8. The projections s and s on thesupports S and S bear, respectively, against the end plates E and E ofthe armature-core, and by the tightening of the screw-bolts II II, &c.,the hubs C and C, and with them the supports S and S, are drawn towardeach other against the end rings and hold the armaturecore firmly inposition. Sullicieut distance is allowed between the hubs and the coreto admit of winding the coils. The rings E and E are notched upon theirinner circumference at e and e to receive the edge of the supports S andS, and through which rotation of the core is transmitted from the shaft.Asabove stated, the inner ends of the supports S and S overlap eachother at so, and the ends are preferably halved, as shown in Figs. 3 and5. The successive pairs of supports around the shaft are made to overlapin alternate direc tions, as shown, also, in Fig. 3, which shows thearrangement when the four arms are straightened out. This constructionassists in preventing any relative displacement of the hubs upon theshaft and in rendering the entire structure firm and rigid. The endrings E and E are somewhat thicker than the rings constituting the coreof the armature to cause compression of the rings of the armature-corebetween the tie-bolts and also to receive the strains in thetransmission of rotation from the shaft to the core through the supportsS and S. It is not advisable to make these plates of great thickness,for in such case Foucault currents would be generated therein. It isalso necessary that the tie-bolts be insulated from the plates toprevent the gen eration of currents in the tie-bolts as con-' ductors.If the rings E and E are only moderately thick wh ere the tie-boltsIpass through the pressure of the rings against the bolts would cutthrough the insulation between them under the pressure of rotating thearmature, and to utilize only moderately-thick rings E and E to preventthe formation of Foucault currents and at the same time to givea largebearing-surface between the plate and the tie-boltsis one of the objectsof myinvention. I accomplish this by securing to the rings theaxially-extending projections F and F, through which the tie-bolts passand from which they are insulated by insulating material placed between,as shown by the heavy lines in the figures. Nuts Gand G on the ends ofthetie-bolts serve to d raw the rings together, and insulation is placedbetween the nuts on the bolt and the face of the projection, as shown.The length of these projections is sufficient to give a largebearing-surface on the tie-boltI and prevent cutting of the insulation.The method of securing this projection to the ring, which I have shownin the drawings, is to rivet it on the inside, leaving a shoulderagainst the outside. I do not wish to limit myself in this regard,however, but I may screw it into the ring orsecureitin any other waythat may seem desirable. The coils are wound in the grooves, and afterthe winding is completed insulation put over, (shown at R R in thefigures) and then the exterior binding is put on. This binding is in theform of a laminated sheath made up of thin annular rings of magneticmetal, preferably formed of the same material as the rings of the core.(Shown at P P in the figures.) These rings are insulated from each othereither individually or in groups and take the place of band wires. Theirpurpose is to soften the heating effect of the toothed armature on thepole-pieces and to give the same effect as an iron-clad armature withoutthe great disadvantage of winding which exists in an iron-cladarmature,where the wires are drawn through grooves or inserted throughnarrow openings in them, holes, the. These rings may either be cementedin place or they may be held by the saucer-shaped cups K,which bearagainst the ends of the sheath P and which may be secured to thesupports S and S, as shown in Fig. 1, or directly to the rings E and E(shown in Fig. 4) by means of the screw M, passing through theinsulatingbushing N. These cups are provided with ventilating-holes 7tand are preferably formed of high-resistance metal, such as an alloy ofaluminium and silver, which I call aluminium-silver, which offers aboutfifty times as much resistance as German silver to the passage ofFoucault or other currents which may be generated in it.

Although I have shown the hubs with radially-projecting arms, in whichthe supports are placed, and consider that the better construction, I donotlimitmyself in that regard;

evaoso but if I prefer I may place the supports in grooves cut in anyportion of the hubs, in which they may be secured and from which theymay extend radially.

I claim and desire to secure by Letters Patent- 1. In an armature forelectric machines whereof the core is made up of thin rings or disks,axially-extending projections secured to the end disks or rings throughwhich the tie-bolts pass and from which they are insulated.

2. In an armature for electric machines whereof the core is made up ofthin rings or disks insulated from each other, a thicker ring or disk onthe end of the core, having axially-extending projections securedthereto, in combination with tie-bolts passing through the projectionsand insulated therefrom.

8. In an armature for electric machines whereof the core is made up ofthin rings or disks insulated from each other, a thicker ring or disk oneach end of the core, provided with axially-extending projections, saidprojections being provided with a shoulder hearing against the outerside of the ring and riv eted on the inner side, in combination withtie-rods passing through the projections and insulated therefrom.

4. In an armature for electric machines, a laminated sheath surroundingthe coils and the core, said sheath consisting of a series of thinannular metallic rings insulated from the coils and the core.

5. In an armature for electric machines, a laminated sheath surroundingthe coils and the core, said sheath consisting of a series of thinannular rings of magnetic metal insulated from the coils and from thecore.

6. In an armature for electric machines, a laminated sheath surroundingthe core and the coils, said sheath consisting of a series of thinannular rings of soft iron insulated from the coils and the core.

7. In an armature for electric machines whereof the coils are wound ingrooves in the core, a laminated sheath covering the coils and the coreand insulated therefrom, said sheath consisting of thin annular rings ofsoft iron.

8. In an armature for electric machines, a laminated sheath covering thecoils and the core and insulated therefrom, said sheath consisting of aseries of thin annular metal lic rings and retained in position by capsrotatin g with the armature and bearing against the ends of the sheath.

9. In an armature for electric machines, a laminated sheath covering thecoils and the core and insulated therefrom, said sheath consisting of aseries of thin annular metallic rings,in combination with caps securedto the armature and insulated therefrom and bearing against the ends ofthe sheath.

10. In an armature for electric machines, a laminated sheath coveringthe coils and the core and insulated therefrom, said sheath IIOconsisting of a series of thin annular metallic rings, in combinationwith caps bearing against the ends of the sheath and rotating with thearmature and provided with ventilating-holes.

11. In an armature for electric machines, a laminated sheath coveringthe coils and the core and insulated therefrom, said sheath consistingof a series of thin annular metal lic rings, in combination with caps ofaluminium-silver rotating with the armature and bearing against the endsof the sheath.

12. In a ring-armature for electric machines, the combination of theshaft, two hubs mounted thereon, supports secured to the hubs andinsulated therefrom, those of one hub bearing against one end of thearmature-core and those of the other hub bearing against the other endof the armature-core, and means for drawing the hubs together on theshaft and clamping the core between the supports, coils upon thearmature-core, and a laminated sheath covering the coils and insulatedtherefrom, with caps secured to the supports borne by the hubs,insulated therefrom, and bearing against the ends of the sheath.

13. In a ring-armature, in combination with the core and the shaft, twohubs mounted upon the shaft, supports secured to the hubs and insulatedtherefrom, those of one hub bearing against one end of the armature-coreand those of the other hub bearing against the other end of thearmature-core, and means for forcing the hubs toward each other on theshaft and clamping the armature-core between the supports.

14. In a ring-armature, in combination with the core and the shaft, twohubs mounted upon the shaft, supports secured to the hubs and insulatedtherefrom, those of each hub overlapping those of the other between thehubs and bearing against the respective ends of the armature-core, withbolts passing through the two hubs and adapted to draw the hubstogether, whereby the core is clamped between the supports,substantially as described.

15. In a ring-armature, two hubs mounted upon the armature-shaft,supports secured to the hubs and insulated therefrom and bearing againstthe inner side of the core, the supports secured to each hub overlappingthose of the other in alternate order between the hubs and bearingagainst the respective ends of the armature-core, with bolts passingthrough the hubs and adapted to draw them together, whereby the core isclamped between the supports.

16. In a ring-armature, in combination with the core, two hubs mountedupon the armatore-shaft, supports secured to the hubs and insulatedtherefrom and bearing against the inner side of the core, the supportssecured to each hub overlapping those of the other between the hubs andbearing against the respective ends of the armature-core, with boltspassing through the hubs, adapted to draw them together, whereby thecore is clamped between the supports.

ELMER A. SPERRY.

Witnesses:

W. R. GOODMAN, M. NIELSON.

